Controlled Polymerisation

1
Controlled Polymerisation

• D M Haddleton
• CH404
• Synthetic Chemistry III

2
Polymers in everday use

• Mechanical properties
• New applications
• Personal care products
• Pharmaceutical Applications
• BASF, Unilever, Geltex, Avecia, etc

3
Control over Polymer architecture

• Graft Copolymers
• Star copolymers
• Dendrimers
• Non covalent crosslinking
• Branching
• Narrow MWD
• Blocks

4
Control
5
Living Polymerisation

• Rate of termination ? 0
• Rate of Initiation gt Rate of Propagation
• Then
• PDi (Mw/Mn) 1 1/DP

6
Test for Living Polymerisation
7
Living Polymerisation

• Anionic
• Cationic
• Ring Opening

8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
Commercial impact of living/controlled
polymerisation

• Anionic Polymerisation is the most established
  form of living polymerisation
• Although discovered in 1956 commercial
  applications have probably not lived up to
  expectations
• Notable exception is styrene-diene block/star
  copolymers (Kraton rubbers)
• Generally anionic polymerisation requires low
  temperatures, solvents which do not chain
  transfer and extremely pure solvents and reagents.

13
Group Transfer Polymerisation
14
(No Transcript)
15
(No Transcript)
16
Free Radical Polymerisation
17
Nitroxide Mediated Radical Polymerisation
18
Reversible Homolytic Dissociation

• Covalent adduct
• Persistent radical

19
Acc. Chem. Res., 30 (9), 373 -382, 1997
20
Variation in experimentally determined molecular
weight, Mn, and the theoretical molecular
weights for thepolymerization of styrene at 125 C
using varying amounts of the unimolecular
initiator 9.
21
CRP of Styrene in Bulk

• T 393 K
• L0 5 10-2 M

22
Library of alkoxyamine structures evaluated as
initiators for the living free radical
polymerization of styrene and n-butyl acrylate.
23
TEMPO
24
Living Polymerisation of Dienes
25
(No Transcript)
26
Reversible Addition Fragmentation Polymerisation

• RAFT

27
RAFT Polymerisation
28
Macromolecules, ASAP Article 10.1021/ma991451a
S0024-9297(99)01451-5 Web Release Date January
6, 2000
29
GPC traces of (a) PMA prepared using 5 and (b)
the same PMA treated with ethylenediamine in THF
at room temperature
30
Generalized Addition-Fragmentation
31
Addition - Fragmentation
32
Atom TransferPolymerisation
33
(No Transcript)
34
(No Transcript)
35
K. Matyjaszewski Macromolecules 1997, 30, p7697
7042 7034 7348 8161 7692 6507, 6513, 6398
JACS 1997, 119, p674 V Percec Macromolecules
1997, 30, p6705, 8526 M Sawamoto Macromolecules
1997, 30, p2244, 2249 Teyssie Macromolecules
1997, 30, p7631, Haddleton Macromolecules 1997,
30, p2190
36
Macromolecules, 30 (25), 7697 -7700, 1997.
37
Macromolecules, 31 (4), 1064 -1069, 1998
38
(No Transcript)
39
Macromolecules, 31 (20), 6762 -6768, 1998
Jiro Ueda, Masami Kamigaito, and Mitsuo Sawamoto
40
Macromolecules, 31 (20), 6756 -6761, 1998
Hiroko Uegaki, Yuzo Kotani, Masami Kamigaito,
and Mitsuo Sawamoto
41
Macromolecules, 32 (7), 2204 -2209, 1999
42
(No Transcript)
43
Reaction rate dependence on the Cu(I)
44
Too much catalyst leads to problems of cost
and residual metal in products. Rate can be
accelerated Reduction of copper(II) to
copper(I) e.g. disproportionation with
copper(0) - Matyjaszewski Addition of rate
enhancers e.g. acid, alcohols Use of mildly
co-ordinated solvents However, for many
applications we require Much lower levels of
metal Recycling of metal Acceptable rates of
polymerisation
45
(No Transcript)
46
Synthesis of Initiators from alcohols
47
?- Functional polymers from functional initiators
based on phenols
48
Catalytic Chain Transferfor Molecular Weight
Control inFree-Radical Polymerisation
49
Measurement of Chain Transfer Constants
50
Polymerisation of MMA at 60 C with COBF
51
Types of Catalysts
52
Mechanism of CCTP
53
CCT Agents
54
Acrylate Monomers
55
Comparison of Catalysts
56
Generalized Addition-Fragmentation
57
Addition - Fragmentation
58
(No Transcript)
59
Further reaction of CCTP macromonomer products
60
(No Transcript)